Transponders are radio communication appliances which are increasingly often used for identifying a wide variety of objects. In comparison with conventional bar code patterns, which are likewise used for identification, transponders have a greater storage capacity. Transponders are designed such that data can be transferred to and read from the transponder by radio. Transponders are now available from various manufacturers and can be used in a mixed mode with other appliances, since they are compatible on the basis of their standardization. During its manufacture, each individual transponder is usually provided with an explicit, invariable and readable identifier in the form of a transponder identification information unit, which means that no two transponders exist with the same transponder identification information unit. By attaching a transponder, it is therefore possible to explicitly identify any objects. Information stored on the transponder is stored invisibly to humans, however, and therefore cannot be read by the human eye.
On the basis of this, the use of transponders in power plants and many commercial installations in order to assist and simplify a wide variety of processes in maintenance work and maintenance measures is regarded with scepticism.
A large amount of the maintenance work and maintenance measures in commercial installations is accompanied by a process of what is known as disconnecting a component before the start of the work and measures and reconnecting the component when the work is concluded. Disconnection is generally understood to mean producing a state in which no voltage is present on electrical installations or components, and also comprises the possibly manual performance of switching actions on mechanical installations, such as the operation of manually operated valves. Particularly before the start of work for maintenance work and maintenance measures, it is necessary for the component to be disconnected without error—that is to say for the component to be effectively “switched off”—so that the safe performance of the work in situ, i.e. on the component, is assured. When the component is reconnected, it is necessary to ensure that work performed in parallel on this component has also been concluded altogether before the component is connected and hence restarted. This reconnection is also referred to as normalization of the component.
The process of disconnection has been assisted for a relatively long time by a computer-aided method which manages the planning and performance of disconnection operations on individual components and also entire procedural systems by creating disconnection lists with individual disconnection steps which are output on paper. Example activities for performing an individual disconnection step are the manual closure of a mechanical valve or the stopping of an electric motor with subsequent removal of the fuse in order to prevent inadvertent reconnection. The disconnection steps are performed using the disconnection plan in the commercial installation, are rendered visually recognizable in situ by attaching adhesive labels, signs, markers or the like and are confirmed as performed on the disconnection list by means of a signature. When all the disconnection steps associated with a component have been performed and this has been checked using the disconnection list, it is possible to give the go-ahead for performing maintenance work and maintenance measures on the relevant component while ensuring a safe work area. The maintenance work and maintenance measures themselves should likewise be performed and confirmed using a list. Only after checking whether all the work and measures to be performed have been concluded can the relevant component be reconnected. The component is reconnected (what is known as normalization) using the disconnection list which needs to be worked through. This also includes removing the attached adhesive labels, signs, markers or the like. This concludes the disconnection operation.
In commercial installations, however, it is not uncommon for several disconnection steps to be simultaneously active on one component of the installation and furthermore for disconnection steps in several active disconnection plans to relate to the same technical component. In this case, it is necessary to ensure that this individual component is disconnected for as long as just one of the simultaneously performed pieces of work is still in progress. Before the normalization is performed, it is therefore necessary to check whether one or more components quoted in the disconnection steps of one disconnection are also included in other active disconnection operations. Should this be the case then it is necessary to exclude this step from the normalization. This task is difficult and potentially susceptible to error, since each disconnection step needs to be checked against each disconnection step in all other active disconnection plans. Although the use of a computer-aided method of conflict recognition as addressed above increases the reliability of the check significantly, computer-aided disconnection does not stretch to the actual location of the disconnection, which means that human error can result in the disconnection of a component despite precise guidelines.
Furthermore, it is possible for the disconnection to be reversed for an incorrect component because an annotation or marker indicating the disconnection is not present on the component, is illegible or is inaccurate. Another source of error which can result in the disconnection of a component being reversed is harboured by paper-based evaluation of a disconnection plan as a result of the overlooking of still active disconnection states, so that an individual component is incorrectly normalized, i.e. connected or switched on. Another risk of unwanted reversal of the disconnection results from a marker which has been attached to the component or to a switching point for this component in this regard having fallen off or being unrecognizable or having been inadvertently removed.